break dop constraints in python dop solver

[catchyid]

Hi, 

I am using Script solver inside a DOP RBD bullet sim, I was able to change velocities of individual RBD packed objects, however I don't know how to access/modify constraints network parameters (e.g strength, add/remove broken group, etc.)? The constraint network in defined globally "Relationships" subdata (i.e. not attached to each object), below is the code I am trying to write :

from __future__ import with_statement

def solveForObjects( solver_data, new_dop_objects, existing_dop_objects, time, timestep):

    dopsim = solver_data.simulation()
    relationships   = dopsim.findRelationship("constraintnetwork1")
    constraintsnetwork = relationships.findSubData("constraintnetwork") # geometry lives inside 'constraintnetwork' subdata
    geo = constraintsnetwork.findSubData("Geometry") #that works, but it's not a hou.Geometry that can be edited!
    with    constraintsnetwork.editableGeometry() as geo: #error: AttributeError: 'DopData' object has no attribute 'editableGeometry
        #.... do something here

 

[catchyid]

did some investigating, it's possible to break constraints also but they must be attached to objects (and not the generic relationship subdata), attached file is an example if someone is interested

pythonrbdscript.hip

[Benyee]

On 2020/11/29 at 11:34 AM, catchyid said:

Hi, 

I am using Script solver inside a DOP RBD bullet sim, I was able to change velocities of individual RBD packed objects, however I don't know how to access/modify constraints network parameters (e.g strength, add/remove broken group, etc.)? The constraint network in defined globally "Relationships" subdata (i.e. not attached to each object), below is the code I am trying to write :

from __future__ import with_statement

def solveForObjects( solver_data, new_dop_objects, existing_dop_objects, time, timestep):

    dopsim = solver_data.simulation()
    relationships   = dopsim.findRelationship("constraintnetwork1")
    constraintsnetwork = relationships.findSubData("constraintnetwork") # geometry lives inside 'constraintnetwork' subdata
    geo = constraintsnetwork.findSubData("Geometry") #that works, but it's not a hou.Geometry that can be edited!
    with    constraintsnetwork.editableGeometry() as geo: #error: AttributeError: 'DopData' object has no attribute 'editableGeometry
        #.... do something here

 

u should just modify some code,like this:

from __future__ import with_statement

def solveForObjects(solver_data, new_dop_objects, existing_dop_objects, time, timestep):
    frame=time/timestep
    sim=solver_data.simulation()
    cnst_rel=sim.findRelationship('constraintnetwork1')
    
    for dop_object in existing_dop_objects:
        with cnst_rel.editableGeometry('constraintnetwork/Geometry') as geo_cnst:
            for prim in geo_cnst.prims():
                if(prim.attribValue('angle')>.2):
                    prim.setAttribValue('constraint_name','Glue')